Rebun Island (礼文島, Rebun-tō; Ainu: Repun) is an island in the Sea of Japan off the northwestern tip of Hokkaidō, Japan. The island sits 50 kilometres (31 mi) off the coast of Hokkaidō. Rebun stretches 29 kilometres (18 mi) from north to south and 8 kilometres (5.0 mi) from east to west. The island covers approximately 80 square kilometres (31 sq mi).